<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    body {
      display: flex;
      justify-content: center;
      align-items: center;
      width: 100%;
      height: 100vh;
      background-color: #000;
    }

    ul {
      list-style: none;
      height: 200px;
      display: flex;
    }

    li {
      width: 20px;
      height: 20px;
      border-radius: 10px;
      background-color: #F44336;
      margin-right: 20px;
    }

    li:nth-child(1) {
      background-color: #F44336;
      animation: love1 4s 0s infinite;
    }

    li:nth-child(2) {
      background-color: #E91E63;
      animation: love2 4s .2s infinite;
    }

    li:nth-child(3) {
      background-color: #9C27B0;
      animation: love3 4s .4s infinite;
    }

    li:nth-child(4) {
      background-color: #673AB7;
      animation: love4 4s .6s infinite;
    }

    li:nth-child(5) {
      background-color: #1976D2;
      animation: love5 4s .8s infinite;
    }

    li:nth-child(6) {
      background-color: #FFEB3B;
      animation: love4 4s 1s infinite;
    }

    li:nth-child(7) {
      background-color: #FF9800;
      animation: love3 4s 1.2s infinite;
    }

    li:nth-child(8) {
      background-color: #FF5722;
      animation: love2 4s 1.4s infinite;
    }

    li:nth-child(9) {
      background-color: #F44336;
      animation: love1 4s 1.6s infinite;
    }

    @keyframes love1 {

      30%,
      50% {
        height: 60px;
        transform: translateY(-30px);
      }

      70%,
      100% {
        height: 0;
        transform: translateY(0);
      }
    }

    @keyframes love2 {

      30%,
      50% {
        height: 125px;
        transform: translateY(-60px);
      }

      70%,
      100% {
        height: 0;
        transform: translateY(0);
      }
    }

    @keyframes love3 {

      30%,
      50% {
        height: 160px;
        transform: translateY(-75px);
      }

      70%,
      100% {
        height: 0;
        transform: translateY(0);
      }
    }

    @keyframes love4 {

      30%,
      50% {
        height: 180px;
        transform: translateY(-60px);
      }

      70%,
      100% {
        height: 0;
        transform: translateY(0);
      }
    }

    @keyframes love5 {

      30%,
      50% {
        height: 200px;
        transform: translateY(-45px);
      }

      70%,
      100% {
        height: 0;
        transform: translateY(0);
      }
    }
  </style>
</head>

<body>

  <ul>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
  </ul>

</body>

</html>